There have been many documented cases of congenital Lyme disease. Many are on this web page. First here is Schlesinger et al.
Maternal-Fetal Transmission of the Lyme Disease Spirochete, Borrelia burgdorferi
Her infant born at 35 weeks gestational age, died of congenital heart disease during the first week of life.
Histologic examination of autopsy material showed the Lyme disease spirochete in the spleen, kidneys, and bone marrow
Image B is a Lyme spirochete in the infants spleen.
Images C, D are Lyme spirochetes in the infants kidney,
Image E are Lyme spirochetes in the infants bone marrow.
This is transplacental transmission of the Lyme disease spirochete to the infants organs.
This is congenital Lyme disease.
Figure 1. ...
autopsy spleen sample showing a single spirochete (arrow) near a fibrous trabeculum (B);
proximal convoluted renal tubules showing B. burgdorferi (C, D) (note the absence of inflammatory cells); and
spirochetes in sections of bone marrow (arrows), with the top micrograph showing a particularly long spirochete (E).
All sections stained by a modified Dieterle silver impregnation method (original magnification, X 1250).